Horrible noise from Cat 3535

[Rudy]

My automatic bay's Cat 3535 started making a horrible "knocking" sound. It almost sounds metallic. Worried that I had either a bad bearing in either the pump or the electric motor I started troubleshooting. The belt (cog style, tripple grooved) is original, but 17 years old. It looked fine, but maybe slightly loose. I tighten it up a little, but the noise remains. I then spray the belt with belt dressing, and the horrible noise goes away. (It can't be a bearing...correct?).

Anyway, that was last night, and the bad noise is back. Can this belt which appears to "look" fine....actually be the problem?

It's just hard for me to believe that you could get a metallic sound from a bad belt?????

 

[jprb]

If you have filters or strainers on the incoming water to the pump, check that those are clean. They will make a "hammering" noise when starved for water.

JPRB

 

[Rudy]

Thanks for the reply... Wouldn't the belt dressing on the belt eliminate that as an issue?

 

[MEP001]

Wouldn't the belt dressing on the belt eliminate that as an issue?

Any noise that goes away from spraying the belt with dressing narrows the problem down to the belt. It couldn't possibly lubricate a failing and noisy motor bearing.

Now that you've sprayed that cog belt with dressing, you should replace it right away. It will cause the rubber to harden and make it fail even faster.

 

[ibspuds]

I would remove the belt, turn water supply "off", manually turn the pump pulley to see if feels funny or you hear a strange noise.

 

[Rudy]

Yup, the new belt quieted things down nicely. What I can't figure out is how a bad (hardened I guess) belt can cause such a distressing sound. In the words of my manager, "That thing sounds like its going to blow up!".